Is there an efficient way to check the usage for PV/PVC in Kubernetes

Question

For example, I have 50 Gib PV/PVC and grant to one Pod, I just want to check usage of the storage

The way I am just following is to set up a busybox pod with mounting the same PVC, then exec into the busybox to run df -h to check the storage.

I just want to know if there is an efficient way to do the same thing.

Answer 1

Depending on how often you need to do this you might look at the df-pv plugin for kubectl https://github.com/yashbhutwala/kubectl-df-pv

It does exactly what you are asking across all the pvs in a namespace or cluster. Once you've got it installed, just run kubectl df-pv and you are set.

Answer 2

You can try the below set of commands, I checked on AKS and found out it to be working fine.

kubectl get pods -n namespace1

Pick the pod_name currently using or mapped to the PV/PVC (Persistent Volume Claims) and since I used the mount directory on the PV hence I have used /mount to check its details & replace {pod_name} with actual pod_name.

kubectl exec -it {pod_name} -n namespace1 bash

df -h

ls -l /mount

Answer 3

Unfortunately we don't have this at the moment. What I often do is querying on Prometheus (because I have a Prom cluster there) for the metrics kubelet_volume_stats_used_bytes for the information.

Or in the harder way, you can write an operator to watch a CRD which wraps the PVC and to display the usage of the PVC.